Multi-scale laser speckle correlation imaging with the low-frequency acquisition

Laser speckle contrast imaging (LSCI) is a relatively mature blood flow visualization technique. However, the existing laser speckle imaging technology has limited spatial resolution due to the difficulty of quantifying the flow rate per pixel and selecting the algorithm window. In this paper, we propose a new multi-scale laser speckle correlation imaging technique to measure compound hemodynamics in several fields of view. Dynamic light scattering techniques characterizing intensity fluctuations were introduced to compensate for the shortcomings of conventional LSCI. We used ordinary research cameras for multi-scale imaging at lower frequencies. The relative image sharpness metric of the β map was improved by 2.25 times of the τ map calculated from the same model, and the β map was more conducive to the study of vascular morphology. Thus, the scheme also exhibited the potential for clinical application in angiography.